Read by QxMD icon Read

Forensic DNA

Yael Herman, Ilan Feine, Ron Gafny
The precise and efficient detection of semen and saliva in sexual assault case-work items is a critical step in the forensic pipeline. The outcome of this stage may have a profound impact on identifying perpetrators as well as on the investigation process and the final outcome in court. Semen detection is usually based on the activity of acid phosphatase (AP), an enzyme found in high concentration in the seminal plasma. Amylase, an enzyme catalyzing starch hydrolysis is found in high concentrations in saliva and therefore is a useful target for its detection...
April 30, 2018: Forensic Science International
Lev Voskoboinik, Uzi Motro, Ariel Darvasi
Interpretation of complex DNA mixtures is an ongoing challenge in the field of forensic genetics. Commonly used STR markers are quite polymorphic, enabling very high statistical association between a single source DNA profile from a crime scene and a matching suspect. STR typing of low order mixtures with two and three contributors also commonly produces high statistical association for a contributor, using current interpretation software. However higher order mixtures, with four contributors or more, are more challenging...
May 2, 2018: Forensic Science International. Genetics
Sarah Seashols-Williams, Raquel Green, Denise Wohlfahrt, Angela Brand, Antonio Limjuco Tan-Torres, Francy Nogales, J Paul Brooks, Baneshwar Singh
Sequencing and classification of microbial taxa within forensically relevant biological fluids has the potential for applications in the forensic science and biomedical fields. The quantity of bacterial DNA from human samples is currently estimated based on quantity of total DNA isolated. This method can miscalculate bacterial DNA quantity due to the mixed nature of the sample, and consequently library preparation is often unreliable. We developed an assay that can accurately and specifically quantify bacterial DNA within a mixed sample for reliable 16S ribosomal DNA (16S rDNA) library preparation and high throughput sequencing (HTS)...
May 17, 2018: Electrophoresis
Nandi Slabbert, Laura Jane Heathfield
Conventional forensic DNA analysis involves a matching principle, which compares DNA profiles from evidential samples to those from reference samples of known origin. In casework, however, the accessibility to a reference sample is not guaranteed which limits the use of DNA as an investigative tool. This has led to the development of phenotype prediction, which uses SNP analysis to estimate the physical appearance of the sample donor. Physical traits, such as eye, hair and skin colour, have been associated with certain alleles within specific genes involved in the melanogenesis pathways...
May 17, 2018: Developing World Bioethics
Salman Shayya, Régis Debruyne, André Nel, Dany Azar
Calliphoridae are among the first insects associated to decomposing animal remains. We have collected 1,841 specimens of three calliphorid genera: Calliphora, Lucilia, and Chrysomya, from different Lebanese localities as a first step in implementing a database of insects of forensic relevance for the country. Blow-flies are crucial for the estimation of the postmortem interval. DNA-based identification is a rapid and accurate method, often used for morphologically similar species, especially for immatures or incomplete specimens...
May 12, 2018: Journal of Medical Entomology
Athina Vidaki, Vivian Kalamara, Elena Carnero-Montoro, Timothy D Spector, Jordana T Bell, Manfred Kayser
Monozygotic (MZ) twins are typically indistinguishable via forensic DNA profiling. Recently, we demonstrated that epigenetic differentiation of MZ twins is feasible; however, proportions of twin differentially methylated CpG sites (tDMSs) identified in reference-type blood DNA were not replicated in trace-type blood DNA. Here we investigated buccal swabs as typical forensic reference material, and saliva and cigarette butts as commonly encountered forensic trace materials. As an analog to a forensic case, we analyzed one MZ twin pair...
May 14, 2018: Genes
Lakshmi Chaitanya, Krystal Breslin, Sofia Zuñiga, Laura Wirken, Ewelina Pośpiech, Magdalena Kukla-Bartoszek, Titia Sijen, Peter de Knijff, Fan Liu, Wojciech Branicki, Manfred Kayser, Susan Walsh
Forensic DNA Phenotyping (FDP), i.e. the prediction of human externally visible traits from DNA, has become a fast growing subfield within forensic genetics due to the intelligence information it can provide from DNA traces. FDP outcomes can help focus police investigations in search of unknown perpetrators, who are generally unidentifiable with standard DNA profiling. Therefore, we previously developed and forensically validated the IrisPlex DNA test system for eye colour prediction and the HIrisPlex system for combined eye and hair colour prediction from DNA traces...
April 12, 2018: Forensic Science International. Genetics
Rebecca Richards, Jayshree Patel, Kate Stevenson, SallyAnn Harbison
Epigenetics is an emerging area of interest in forensic science. DNA methylation, a type of epigenetic modification, can be applied to chronological age estimation, identical twin differentiation and body fluid identification. However, there is not yet an agreed, established methodology for targeted detection and analysis of DNA methylation markers in forensic research. Recently a massively parallel sequencing-based approach has been suggested. The use of massively parallel sequencing is well established in clinical epigenetics and is emerging as a new technology in the forensic field...
May 11, 2018: Electrophoresis
Lindsay M Freeman, Lin Pang, Yeshaiahu Fainman
The analysis of DNA has led to revolutionary advancements in the fields of medical diagnostics, genomics, prenatal screening, and forensic science, with the global DNA testing market expected to reach revenues of USD 10.04 billion per year by 2020. However, the current methods for DNA analysis remain dependent on the necessity for fluorophores or conjugated proteins, leading to high costs associated with consumable materials and manual labor. Here, we demonstrate a potential label-free DNA composition detection method using surface-enhanced Raman spectroscopy (SERS) in which we identify the composition of cytosine and adenine within single strands of DNA...
May 9, 2018: Scientific Reports
Yaran Yang, Weini Wang, Feng Cheng, Man Chen, Tong Chen, Jing Zhao, Chong Chen, Yan Shi, Chen Li, Chuguang Chen, Yacheng Liu, Jiangwei Yan
Y chromosome Short tandem repeats (Y-STRs) analysis has been widely used in forensic identification, kinship testing, and population evolution. An accurate understanding of haplotype and mutation rate will benefit these applications. In this work, we analyzed 1123 male samples from Northern Chinese Han population which including 578 DNA-confirmed father-son pairs at 22 Y-STRs loci. A total of 537 haplotypes were observed and the overall haplotype diversity was calculated as 1.0000 ± 0.0001. Except that only two haplotypes were observed twice, all the rest of the 535 were unique...
May 8, 2018: Scientific Reports
Katelyn Elizabeth Mason, Deon Anex, Todd Grey, Bradley Hart, Glendon Parker
Bone tissue contains organic material that is useful for forensic investigations and may contain preserved endogenous protein that can persist in the environment for extended periods of time over a range of conditions. Single amino acid polymorphisms in these proteins reflect genetic information since they result from non-synonymous single nucleotide polymorphisms (SNPs) in DNA. Detection of genetically variant peptides (GVPs) - those peptides that contain amino acid polymorphisms - in digests of bone proteins allows for the corresponding SNP alleles to be inferred...
April 22, 2018: Forensic Science International
Yuancun Zhao, Xiaogang Chen, Yiwen Yang, Xiaohong Zhao, Shu Zhang, Zehua Gao, Ting Fang, Yufang Wang, Ji Zhang
Diatom examination has always been used for the diagnosis of drowning in forensic practice. However, traditional examination of the microscopic features of diatom frustules is time-consuming and requires taxonomic expertise. In this study, we demonstrate a potential DNA-based method of inferring suspected drowning site using pyrosequencing (PSQ) of the V7 region of 18S ribosome DNA (18S rDNA) as a diatom DNA barcode. By employing a sparse representation-based AdvISER-M-PYRO algorithm, the original PSQ signals of diatom DNA mixtures were deciphered to determine the corresponding taxa of the composite diatoms...
May 7, 2018: International Journal of Legal Medicine
HaiJun He, Lagabaiyila Zha, JinHong Cai, Jian Huang
Autosomal genetic markers and Y chromosome markers have been widely applied in analysis of mixed stains at crime scenes by forensic scientists. However, true genotype combinations are often difficult to distinguish using autosomal markers when similar amounts of DNA are contributed by multiple donors. In addition, specific individuals cannot be determined by Y chromosomal markers because male relatives share the same Y chromosome. X-linked markers, possessing characteristics somewhere intermediate between autosomes and the Y chromosome, are less universally applied in criminal casework...
May 4, 2018: International Journal of Legal Medicine
Stephanie Vallant, Harald Niederstätter, Burkhard Berger, Reinhard Lentner, Walther Parson
Noninvasive sampling, for example, of droppings or feathers, is a promising approach for molecular genetic studies on endangered and elusive animal species. Yet, such specimens are known for containing only minute amounts of DNA, resulting in lower typing success rates relative to analyses on fresh tissues such as muscle or blood. Furthermore, artefactual signals as well as contamination are more likely to occur when DNA is limited. To increase the reliability of DNA typing from noninvasive samples, optimized DNA extraction and polymerase chain reaction protocols were developed, taking advantage of developments in the forensic field aiming at successful molecular genetic analysis of DNA templates being low in quality and quantity...
April 2018: Ecology and Evolution
John T Wixted, Laura Mickes, Ronald P Fisher
Although certain pockets within the broad field of academic psychology have come to appreciate that eyewitness memory is more reliable than was once believed, the prevailing view, by far, is that eyewitness memory is unreliable-a blanket assessment that increasingly pervades the legal system. On the surface, this verdict seems unavoidable: Research convincingly shows that memory is malleable, and eyewitness misidentifications are known to have played a role in most of the DNA exonerations of the innocent. However, we argue here that, like DNA evidence and other kinds of scientifically validated forensic evidence, eyewitness memory is reliable if it is not contaminated and if proper testing procedures are used...
May 2018: Perspectives on Psychological Science: a Journal of the Association for Psychological Science
Claire L Glynn, Kelsie R O Leary
BACKGROUND: The discovery of forensic DNA typing evolved molecular biology far beyond what could have been expected in terms of its forensic application, and now there exists other developments in molecular biology which are ready for application to forensic challenges. One such challenge is the identification of the body fluid source of stains recovered from evidence items and crime scenes. Currently there are significant efforts in the research field to develop novel methods for the molecular identification of body fluids, with microRNAs (miRNAs) revealing great potential...
April 30, 2018: MicroRNA
R Owers, G Davidson, A McDonald, R Morgan, P O'Rourke
Time since intercourse (TSI) expectations are dependent on the method used to recover spermatozoa from vaginal swabs. TSI data following Sperm Elution™ is presented from a large scale study of 2269 cases of penile-vaginal penetration sexual assault allegations analysed by Cellmark Forensic Services and is compared to published TSI data generated using two different water-based elution methods Sperm Elution recovered spermatozoa in 32% of cases analysed where the alleged offence had occurred 3-4 days previously, significantly above the level detected using other elution methods...
April 14, 2018: Forensic Science International
Shu Zhang, Qiang Zhu, Xiaogang Chen, Yuancun Zhao, Xiaohong Zhao, Yiwen Yang, Zehua Gao, Ting Fang, Yufang Wang, Ji Zhang
Insertion/deletion polymorphisms (InDels), which possess the characteristics of low mutation rates and a short amplicon size, have been regarded as promising markers for forensic DNA analysis. InDels can be classified as bi-allelic or multi-allelic, depending on the number of alleles. Many studies have explored the use of bi-allelic InDels in forensic applications, such as individual identification and ancestry inference. However, multi-allelic InDels have received relatively little attention. In this study, InDels with 2-6 alleles and a minor allele frequency ≥0...
April 27, 2018: Electrophoresis
Tetsuya Satoh, Seiya Kouroki, Keita Ogawa, Yorika Tanaka, Kazutoshi Matsumura, Susumu Iwase
Identifying body fluids from forensic samples can provide valuable evidence for criminal investigations. Messenger RNA (mRNA)-based body fluid identification was recently developed, and highly sensitive parallel identification using reverse transcription polymerase chain reaction (RT-PCR) has been described. In this study, we developed reverse transcription loop-mediated isothermal amplification (RT-LAMP) as a simple, rapid assay for identifying three common forensic body fluids, namely blood, semen, and saliva, and evaluated its specificity and sensitivity...
April 25, 2018: Analytical and Bioanalytical Chemistry
Ji Hye Park, Sang Eon Shin, Kwang Soo Ko, Seong Hwan Park
Estimation of postmortem interval (PMI) is paramount in modern forensic investigation. After the disappearance of the early postmortem phenomena conventionally used to estimate PMI, entomologic evidence provides important indicators for PMI estimation. The age of the oldest fly larvae or pupae can be estimated to pinpoint the time of oviposition, which is considered the minimum PMI (PMImin ). The development rate of insects is usually temperature dependent and species specific. Therefore, species identification is mandatory for PMImin estimation using entomological evidence...
2018: BioMed Research International
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"